“瞧我这烂记性”用英语怎么说

Oh, it's nearly slipped my mind.
哦，我差点忘了！

Now where was I?
我说到哪儿了？

Sorry, my mind's gone blank.
对不起，我的记忆一片空白。

I have no recollection of meeting him.
我不记得见过他。

I can't really recall.
我真的想不起来了。

I've completely forgotten.
我彻底忘记了。

I do have a memory like a sieve.
我记性特别不好。

What was I thinking of?
我当时是怎么想的？